Young Cape Verde sea turtles, new study


This video from Florida in the USA is called Loggerhead Turtle burying eggs and returning to the ocean.

From Phys.org:

Sea turtles’ first days of life: Scientists follow hatchlings from Cape Verde with tiny acoustic transmitters

Oct 23, 2014

With new nano-sized acoustic transmitters, scientists from GEOMAR Helmholtz Centre for Ocean Research Kiel, the Turtle Foundation and Queen Mary University of London followed the pathways of loggerhead turtle hatchlings. According to the study, which was primarily funded by the Kiel Cluster of Excellence ‘The Future Ocean,’ local oceanic conditions are believed to drive the evolution of some unique swimming behaviors. The results are published in the Proceedings of the Royal Society B.

Loggerhead turtles (Caretta caretta) from Cape Verde start their life with a swimming sprint and a ride on favourable ocean currents. In this way, they escape quickly from predator-rich coastal areas and make their way to the safer open ocean where they spend several years feeding and growing. In this study, tiny acoustic transmitters provided direct insight into these pathways for the first time. “Thanks to the new technology we can start to fill in key information gaps about the so-called ‘lost years’ Dr. Rebecca Scott states. Funded by the Kiel Cluster of Excellence “The Future Ocean”, the marine biologist coordinated a joint study of GEOMAR Helmholtz Centre for Ocean Research Kiel, the Turtle Foundation and the School of Biological and Chemical Sciences at the Queen Mary University of London.

“Scientists call this early life phase the ‘lost years’, because they were not able to follow new-born sea turtle hatchlings very far. Hatchlings essentially disappear into the sea until many years later when the lucky survivors return to where they born to breed”, Dr. Scott says. But with new techniques like nano-tags and ocean models we are able to see where the tiny young animals go. This is important because the dispersal experiences of hatchlings drive the development of their behaviours into adulthood. The more we understand about the biological and physical determinants of their dispersal and swimming behaviours, the easier we can protect this endangered species.”

In cooperation with the Turtle Foundation at Boa Vista, Cape Verde, the scientists collected hatchlings from two beaches in the northwest and southern tip of the island. Acoustic transmitters with a five millimetres wide and twelve millimetres long streamlined shape that weigh 0,4 grams in water were glued onto the shell of eleven hatchlings. The turtles were then followed at sea using a boat and acoustic receiver for up to eight hours and 15 kilometres. In addition, the swimming behaviour of 16 hatchlings were monitored in “hatchling swimming pools” for several days using data loggers made by engineers at GEOMAR. The turtles swam continuously during their first 24 hours after hatching and then switched to a pattern of activity at daytime and inactivity at night.

Due to the close proximity of offshore currents in this region, it seems the Cape Verdean hatchlings can sleep more at night than hatchlings from other places. For example in America, different research groups have shown that they would have swim a lot more to reach offshore currents”, Dr. Scott explains. “Deep oceanic water and favourable currents, which then determined the travel directions and speeds of our Cape Verdean turtles are situated very near to their nests. Therefore, it is very beneficial for turtles if local oceanic conditions drive the evolution of swimming behaviours that are unique to different nesting locations to ensure their best survival outcomes. It seems that turtles are born with these unique locally adapted behaviours.”

Finally, because larger animals kept swimming for a longer time than smaller individuals, a larger body size is thought to be a good sign of fitness. “But there is some evidence emerging that higher nest temperatures may reduce the size of hatchlings. Therefore, it might be possible that global warming decreases the fitness of the sea turtles by threatening them in more subtle ways than just obvious dangers like the loss of nesting beaches”, Dr. Scott assumes.

Florida green anoles adapt to invasive species


This video from the USA says about itself:

The largest Green Anole ever!

The Carolina anole (Anolis carolinensis) is an arboreal lizard found primarily in the southeastern United States and some Caribbean islands. Other common names include the green anole, American anole and red-throated anole. It is also sometimes referred to as the American chameleon due to its ability to change color from several brown hues to bright green. While many kinds of lizards are capable of changing color, anoles are closely related to iguanas and are not true chameleons. The Carolina is a small lizard; male adults are usually 15 cm (5.9 in) long in adulthood, about half of which is its tail, and it can weigh from 3–7 g (0.11–0.25 oz). Exceptionally, these anoles will grow up to 20 cm (7.9 in) in length.

From Breaking News:

A lizard species in Florida has evolved very quickly to deal with invaders

24/10/2014 – 12:16:32

In as little as 15 years, lizards native to Florida – known as Carolina anoles or green anoles – have adapted to deal with the threat of an invading species of lizard, Cuban or brown anoles.

This video is called Egg-laying brown anole (Anolis sagrei), Aruba. This female brown anole was filmed during digging a hole in the sand in which she layed an egg.

After having contact with the invasive species, said to have first gone to America from Cuba in the 1950s, the native lizards starting perching higher up in trees. Over the course of 15 years and 20 generations, their feet evolved to become better at gripping the thinner, smoother branches found higher up.

The change was rapid. After a few months the native lizards started moving higher up the branches and over 15 years, their toe pads had become larger with stickier scales on their feet.

“We did predict that we’d see a change, but the degree and quickness with which they evolved was surprising,” said Yoel Stuart, a post-doctoral researcher in the College of Natural Sciences at The University of Texas at Austin and lead author of the study.

“To put this shift in perspective, if human height were evolving as fast as these lizards’ toes, the height of an average American man would increase from about 5 foot 9 inches today to about 6 foot 4 inches within 20 generations — an increase that would make the average U.S. male the height of an NBA shooting guard,” said Stuart. “Although humans live longer than lizards, this rate of change would still be rapid in evolutionary terms.”

This latest study is one of only a few well-documented examples of what evolutionary biologists call “character displacement,” where similar species competing with each other evolve differences to take advantage of different ecological niches.

A classic example comes from the finches studied by Charles Darwin. Two species of finch in the Galapagos Islands diverged in beak shape as they adapted to different food sources.

The researchers speculate that the competition between brown and green anoles for the same food and space may be driving the adaptations of the green anoles. Stuart also noted that the adults of both species are known to eat the hatchlings of the other species.

“So it may be that if you’re a hatchling, you need to move up into the trees quickly or you’ll get eaten,” said Stuart. “Maybe if you have bigger toe pads, you’ll do that better than if you don’t.”

The research was published in the journal Science.

See also here. And here. And here.

New whale species discovery off Florida?


This video is called Bryde’s whale (Balaenoptera brydei).

From Wildlife Extra:

Possible new whale species could be the world’s most endangered

A new species of whale may have been discovered off the coast of Florida. Scientists previously thought that the group of around 50 whales living in DeSoto Canyon in the Gulf of Mexico were a [sub]species of Bryde’s Whale (pronounced ‘brooda’).

However, new genetic testing indicates that they might in fact be different species, and if so that would make them the most endangered whale on Earth.

The new testing has identified that the whales could be a distinct subspecies of Bryde’s Whale, or they could potentially be a new species altogether.

The DNA sampled in the tests also suggests that there were previously many more of the whales. “It’s unclear based on the genetics exactly when [the decline] occurred,” says Michael Jasny, Director of the Marine Mammal Program at the Natural Resources Defense Council (NRDC), as reported on Mother Nature Network.

“It’s possible humans were involved in the decline, through whaling or industrial activities. There’s a suggestion in the published paper that oil and gas activity might have led to contraction of the range.”

DeSoto Canyon, where the whales live year-round, is adjacent to Mississippi Canyon, where the Deepwater Horizon oil spill occurred in 2010.

Testing carried out on whales in the area after the spill showed high levels of toxic metals, and it is suspected that the new whale species in the Gulf would also have been affected by the incident.

Jasny, who recently petitioned the US government to list the whales as an endangered species, believes that the whale needs protection from local environmental stressors, including shipping noises and the widespread use of seismic ‘airgun’ surveys for oil and gas exploration. The airguns have been banned in the canyon, but continue in nearby areas.

“Sound travels much farther in seawater than it does in air,” Jasny explains. “We know noise from seismic surveys travels particularly far and can have a large environmental footprint. Great whales are especially vulnerable.

“We know that airguns can destroy the ability of whales to communicate, hundreds of miles or in some cases even thousands of miles from a single airgun array. We know it causes great whales to cease vocalizing, and that it can compromise their ability to feed.

“It’s hard to imagine how this population — or possibly this species — would survive without protection.”

Along with other conservationists, Jasny hopes that the species will be listed as endangered, as this will afford it further protection. However the US Fish and Wildlife Service have a backlog of endangered species, which will mean a long waiting period for adding the whale to the list.

Should it be decided that the whale will be added to the list, it will then go to the US Endangered Species Act, which could take two years to process.

Bahamas, built by bacteria from Saharan dust?


This video says about itself:

Wildlife of Exuma Island, Bahamas – Lonely Planet travel video

Visitors to sparsely populated Exuma, a remote island in the Bahamas, can expect a close encounter with sharks and iguanas.

From New Scientist:

Bahamian paradise built by bacteria using Saharan dust

13:40 28 July 2014 by Flora Graham

The Bahamas may have been created by bacteria thriving on minerals in dust from the Sahara desert, 8000 kilometres away.

In this NASA satellite image from 2009, it is possible to see how the many islands of the Bahamas are actually the highest points of distinct areas where the sea is shallow and turquoise.

These turquoise waters mark the top of the Bahama Banks – underwater columns of coral reef limestone more than 4500 metres tall that have formed over the past 100 million years. It was thought that tiny plants and animals generate the vast amounts of carbonate that make up the towers, similar to how coral reefs are formed. But the surrounding sea is poor in nutrients, so what would have sustained them is a mystery.

Now researchers including Peter Swart from the University of Miami’s Rosenstiel School of Marine and Atmospheric Science in Florida are showing that photosynthetic cyanobacteria may actually have done much of the construction.

Cyanobacteria are involved in the precipitation of calcium carbonate in the sea, but they would have needed an enormous amount of iron to do their work. This could have been provided by the dust that blows across the Atlantic from the Sahara.

There are characteristic traces of iron and manganese in recent carbonate sediment on the banks, pointing to their Saharan origin. So the team suggests that the Bahama Banks are being built up by cyanobacteria and may also have been in the past.

The results of this research are here.

Reddish egrets, what do they eat?


This video from the USA is called Crazy Reddish Egret dance hunting for fish, Marco Island, Florida.

From Waterbirds in the USA:

Comparisons of Reddish Egret (Egretta rufescens) Diet During the Breeding Season Across its Geographic Range

Abstract

Although the prey of Reddish Egrets (Egretta rufescens) generally consists of shallow-water, euryhaline fish species, rangewide differences in breeding season diet have not been examined. Furthermore, the relative proportions of the two Reddish Egret color morphs vary from east to west across the species’ range. Color morph may influence foraging efficiency, but variations in prey across the species’ range and between morphs is undocumented.

By examining boluses from Reddish Egret (n = 109) nestlings, prey species proportions were compared between morphs, among regions and among colonies within Texas. Between regions, prey species and proportion of species differed widely; however, fish species with similar life histories were selected across the Reddish Egret’s range (Bahamas: 100% sheepshead minnow (Cyprinodon variegatus); Texas: 85% sheepshead minnow; Baja California Sur: 49% American shadow goby (Quietula y-cauda); Yucatán: 64% Yucatán pupfish (C. artifrons).

Within the Laguna Madre in Texas, significant differences in prey species were not detected between morphs (F(1,61) = 1.36, P = 0.224); however, prey mass by species differed between colonies (F(1,60) = 2.68, P = 0.010). While our results only pertain to Reddish Egret diet during the breeding season, this study increases our understanding of Reddish Egret ecology and provides initial diet information across the species’ range.

Female Bachman’s sparrows singing, new study


This video from Florida in the USA is about a singing male Bachman’s sparrow.

From the Southeastern Naturalist in the USA:

An Unusual Song-like Vocalization Produced by Female Bachman’s Sparrows (Peucaea aestivalis)

Abstract

We describe a new female vocalization for Peucaea aestivalis (Bachman’s Sparrow) that may represent a type of female song. The vocalization has characteristics that are similar to the “excited” or “flight” songs that male P. aestivalis produce, and similar song characteristics can be found among other members of the genus, including one congener for which female singing is common.

Two marked female P. aestivalis were observed producing the vocalization as well as four unmarked individuals that were paired with territorial males. A recording of one of these unmarked individuals collected in 1989 is similar to the vocalizations observed for marked females. Field notes collected at the time the recording was made suggested the “odd song” was produced by a female, and we provide a sonogram of this new vocalization based on this recording. The vocalization appears to be rare and may be difficult to link to external stimuli and social function.